Compositions comprising an ultraviolet radiation-absorbing polymer

ABSTRACT

Ultraviolet radiation-absorbing polymers having a first pendant group that comprises an ultraviolet radiation-absorbing moiety and a second pendant group that comprises at least one siloxane linkage and/or an intermediate length carbon chain are disclosed. Personal care compositions including the ultraviolet radiation-absorbing polymer are provided.

FIELD OF THE INVENTION

The present invention relates to improved sunscreen compounds andtopically-acceptable compositions that include these sunscreencompounds.

BACKGROUND OF THE INVENTION

The prolonged exposure to UV radiation, such as from the sun, can leadto the formation of light dermatoses and erythemas, as well as increasethe risk of skin cancers, such as melanoma, and accelerate skin aging,such as loss of skin elasticity and wrinkling.

Numerous sunscreen compounds are commercially available with varyingability to shield the body from ultraviolet light. For example, thevarious sunscreen compounds may absorb or block ultraviolet differentportions of the ultraviolet spectrum, such as ultraviolet light havingwavelengths in both the UV-A range (from about 320 to 400 nm) and theUV-B range (from about 280 to about 320 nm), or some combination of bothof these spectral ranges.

It has been suggested to use sunscreen molecules having high molecularweights in order to reduce the penetration of the sunscreen moleculethrough the epidermis. However, only a limited number of options forhigh molecular weight sunscreen compounds exist. As such, applicantshave recognized it would desirable to have new polymeric sunscreencompounds (ultraviolet radiation-absorbing polymers) that are suitablefor inclusion in topical sunscreen compositions. It would also bedesirable for the UV-absorbing polymers to, when formulated, providecompositions that are capable of imparting one or more of goodspreadability, low gloss, non-greasy texture, waterproofing, high SPF,high PFA, and favorable PFA/SPF ratio (broad spectrum protection).Applicants have discovered that UV-absorbing polymers comprising a firstpendant group that comprises a UV-absorbing moiety and a second pendantgroup that comprises at least one siloxane linkage and/or anintermediate length carbon chain provide particular advantages, whetherused alone or blended with other UV-absorbing polymers.

SUMMARY OF THE INVENTION

In one aspect, the invention features a UV-absorbing polymer having thefollowing chemical structure:

wherein R₁ is a first pendant group that comprises a UV-absorbingmoiety, such as a UV-A absorbing moiety, preferably a UV-absorbingtriazole; R₂ is a second pendant group that comprises: a) at least one,such as 1 to about 50, siloxane linkages, b) a saturated or unsaturatedhydrocarbon moiety having an intermediate number of carbon atoms, suchas 7 to 16 carbon atoms, or c) a combination thereof; each R′ isindependently H or C₁ to C₁₂ alkyl; n is 1 to 6000; and m is 2 to 6300.In one embodiment, the UV-absorbing polymer has a weight averagemolecular weight of at least about 2000 and comprises at least about 5mole % of R₁. In another embodiment, R₂ is free of UV-absorbingmoieties.

In another aspect, the invention features an aqueous compositioncomprising water and a UV-absorbing polymer having the followingchemical structure:

wherein R₁ is a first pendant group that comprises a UV-absorbingmoiety, such as a UV-A absorbing moiety, preferably a UV-absorbingtriazole; R₂ is a second pendant group that comprises: a) at least one,such as 1 to about 50 siloxane linkages, b) a saturated or unsaturatedhydrocarbon moiety having an intermediate number of carbon atoms, suchas 7 to 16 carbon atoms, or c) a combination thereof; each R′ isindependently H or C₁ to C₁₂ alkyl; n is 1 to 6000; and m is 2 to 6300.In one embodiment, the UV-absorbing polymer has a weight averagemolecular weight of at least about 2000 and comprises at least about 5mole % of R₁. In another embodiment, R₂ is free of UV-absorbingmoieties.

In another aspect, the invention relates to method of protectingmammalian skin or hair from UV radiation comprising topically applyingto the skin or hair the UV-absorbing polymer of the invention.

In another aspect, the invention features a composition that comprises afirst UV-absorbing polymer that includes a UV-A absorbing moiety and asecond UV-absorbing polymer that includes a UV-B absorbing moiety. Theblend is capable of providing both synergistic SPF and synergistic PFAprotection over a mass percent range of the two polymers of at leastabout 40%.

In another aspect, the invention features a composition comprising afirst UV-absorbing polymer that includes a UV-A absorbing moiety; and asecond UV-absorbing polymer that includes a UV-B absorbing moiety,wherein the first UV-absorbing polymer has a PFA/SPF ratio greater than0.3 and the second UV-absorbing polymer has a UV-B absorber has aPFA/SPF ratio less than 0.3.

In another aspect, the invention features a composition comprising: 1) afirst UV-absorbing polymer having a carbon chain (C—C) backbone and thatincludes a UV-A absorbing moiety; and 2) a second UV-absorbing polymerhaving a siloxane backbone and that includes a UV-B absorbing moiety.

In another aspect, the invention features a composition thatcomprises: 1) a first UV-absorbing polymer having an C—C backbone, afirst pendant group that includes a first UV-absorbing moiety and asecond pendant group comprising at least one siloxane group, wherein thesecond pendant group is free of UV-absorbing moieties; and 2) a secondUV-absorbing polymer that includes at least one siloxane and a second UVabsorbing moiety.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows the absorbance spectra for the UV-absorbing polymers ofExamples 5 and 6 and the homopolymer of Example 8.

DETAILED DESCRIPTION OF THE INVENTION

It is believed that one skilled in the art can, based upon thedescription herein, utilize the present invention to its fullest extent.The following specific embodiments are to be construed as merelyillustrative, and not limitative of the remainder of the disclosure inany way whatsoever.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which the invention belongs. Also, all publications, patentapplications, patents, and other references mentioned herein areincorporated by reference. As used herein, unless otherwise indicated,all alkyl, alkenyl, and alkoxy groups may be straight, cyclic, orbranched chain groups. As used herein, unless otherwise indicated, theterm “molecular weight” refers to weight average molecular weight,(M_(w)). The term “mass ratio” as used herein refers to ratio of themass percentage of one component to the mass percentage of a secondcomponent, for example, two UV-absorbing polymers; two monomers that areused to react with one another in a polymerization reaction; or tworepeat units that are present in a polymer after polymerization. Massratio can be expressed either as a ratio of percentages that add up to100%, (e.g., 90%/10%) or in “ratio format” (e.g., 9:1).

UV-Absorbing Polymer

Embodiments of the invention relate to compositions including anultraviolet radiation-absorbing polymer, (i.e., “UV-absorbing polymer”).By “UV-absorbing polymer,” it is meant a polymer that absorbs radiationin some portion of the ultraviolet spectrum (290 nm-400 nm), andpreferably has an extinction coefficient of at least about 1000 mold⁻¹cm⁻¹, for example greater than 10,000 or 100,000 or 1,000,000 mol⁻¹cm⁻¹, for at least one wavelength within the above-defined ultravioletspectrum.

In one preferred embodiment, the UV-absorbing polymer has the chemicalstructure:

-(A)_(n)-(B)_(m)-

The UV-absorbing polymer generally includes n moles of a first repeatunit, A; and m moles of a second repeat unit, B. As such, the inventiveUV-radiation absorbing polymer is a copolymer that has at least tworepeat units. The polymer generally includes a backbone of covalentlybonded carbon atoms (e.g., a carbon chain or C—C backbone) from whichpendant groups are attached.

As will be recognized by those of skill in the art, the “backbone”refers generally to the portion of repeat units in a polymer that arecovalently bonded to adjacent repeat units. If multiple such portionsexist, the backbone is that portion of the polymer molecule having thelargest number of continuous and covalently bonded atoms. Other smallergroups of covalently bonded atoms are considered pendant groups thatbranch from the backbone.

In one embodiment, the UV-absorbing polymer may be represented by thefollowing chemical structure:

In this embodiment, the first repeat unit generally includes firstpendant group, R₁ which is linked to the C—C backbone via, for example,a linking group, e.g., an ester linking group as shown above.

The C—C backbone generally consists of at least about 7 carbon atoms,preferably from about 7 to about 7000 carbon atoms, more preferably fromabout 10 to about 5000 carbon atoms, even more preferably from about 100to about 4000 carbon atoms, and even more preferably from about 200 toabout 3000 carbon atoms.

The first pendant group, R₁, includes a first UV-absorbing moiety (alsoreferred to herein as a “UV-absorbing chromophore,” a “UV chromophore,”or, for simplicity a “chromophore”). The first UV-absorbing moietyabsorbs in the ultraviolet spectrum.

In one particularly preferred embodiment, the first UV-absorbing moietyis a UV-A absorbing moiety. By “UV-A absorbing moiety,” it is meant thatthe moiety has appreciable absorbance in the UV-A portion (320 nm to 400nm) of the ultraviolet spectrum. For example, when a compound thatincludes the particular chemical moiety is cast into a film, it ispossible to generate a molar extinction coefficient measured for atleast one wavelength in this wavelength range of at least about 1000mol⁻¹ cm⁻¹, preferably at least about 2000 mol⁻¹ cm⁻¹, more preferablyat least about 4000 mol⁻¹ cm⁻¹. In a preferred embodiment, the molarextinction coefficient among at least 40% of the wavelengths in thisportion of the spectrum is at least about 1000 mol⁻¹ cm⁻¹.

Examples of moieties that are UV-A absorbing include triazoles such asbenzotriazoles; camphors such as benzylidene camphor and its derivatives(such as terephthalylidene dicamphor sulfonic acid also known asECAMSULE or Mexoryl SX, available from L'Oreal); dibenzoylmethanes andtheir derivatives.

In a particularly preferred embodiment, the UV-absorbing moiety is aUV-absorbing triazole and/or a UV-absorbing benzoylmethane. In a furtherpreferred embodiment, in order to provide both photostability and strongUV-A absorbance, the UV-absorbing moiety is a UV-absorbing triazole.

By “UV-absorbing triazole” it is meant UV-absorbing moiety containing afive-membered heterocyclic ring with two carbon and three nitrogenatoms. UV-absorbing triazoles include, for example, compounds of FormulaI or II:

wherein each R₁₄ is independently selected from the group consisting ofhydrogen, C₁-C₂₀ alkyl, alkoxy, acyl, alkyloxy, alkylamino, and halogen;each of R₁₅ and R₂₂ are independently selected from the group consistingof hydrogen, C₁-C₂₀ alkyl, alkoxy, acyl, alkyloxy, and alkylamino, atleast one of R₁₅ and R₂₂ not being hydrogen; and R₂₁ is selected fromC₁-C₂₀ alkyl, alkoxy, acyl, alkyloxy, and alkylamino.

In Formula I, either of the R₁₅ or R₂₁ groups may be oriented so as tobe directly bonded to the (ester) linking group that connects theUV-absorbing triazole to the C—C backbone. In Formula II, either of theR₁₅ or R₂₂ groups may be oriented so as to be directly bonded to the(ester) linking group that connects the UV-absorbing triazole to the C—Cbackbone.

Monomeric compounds of Formulae I and II are described in U.S. Pat. No.5,869,030, and include, but are not limited to, methylenebis-benzotriazolyl tetramethylbutylphenol (TINSORB M, Ciba SpecialtyChemicals Corporation, Greensboro, N.C., USA). Other monomericUV-absorbing dibenzoylmethanes include 2-(4-diethyl amino-2hydroxybenzoyl)-benzoic acid hexylkester, commercially available asUVINUL A Plus from BASF of Parsippany, N.J.

In one preferred embodiment, the UV-absorbing triazole is a compound ofFormula I in which R₁₄ is a halogen, preferably chlorine, R₁₅ is a butylgroup and R₂₁ is —CH₂CH₂CO₂C₈H₁₇ (which may be converted to an acid formand subsequently converted to an ethylenically unsaturated form in orderto make it suitable for polymerization). Such UV-absorbing triazoles areavailable as a blend ofoctyl-3-[3-tert-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazol-2-yl)phenyl]propionateand its isomer,2-Ethylhexyl-3-[3-tert-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazol-2-yl)phenyl]propionateas TINUVIN 109, from Ciba Inc. (BASF Corporation). Another suitableexample of a UV-absorbing triazole is a transesterification product of2-[3′-tert-butyl-5′-(2-methoxycarbonylethyl)-2′-hydroxyphenyl]-2H-benzotriazolewith polyethylene glycol 300, commercially available as TINUVIN 213,also available from Ciba Inc.

UV-absorbing dibenzoylmethanes include those that may be represented byFormula III:

wherein R₁₉ and R₂₀, independently, are optionally C₁-C₈ alkyl or C₁-C₈alkoxy, m9 is 0 to 3, and m10 is 1 to 3. Either of the R₁₉ and R₂₀ groupmay be oriented so as to be directly bonded to the (ester) linking groupthat connects the UV-absorbing dibenzoylmethane to the C—C backbone.

Examples and the synthesis of such monomeric dibenzoylmethane compoundscompositions are disclosed in U.S. Pat. No. 4,489,057 and include, butare not limited to, 4-(1,1-dimethylethyl)-4′-methoxydibenzoylmethane(avobenzone and sold as PARSOL 1789, Roche Vitamins and Fine Chemicals,Nutley, N.J., USA), 2-2-methyldibenzoylmethane,4-methyl-dibenzoylmethane, 4-isopropyldibenzoylmethane,4-tert-butyldibenzoylmethane, 4-tert-butyl-4′-methoxydibenzoylmethane,2,4-dimethylbenzoylmethane, 2,5-dimethylbenzoylmethane,4,4′-diisopropylbenzoyl methane,2-methyl-5-isopropyl-4′-methoxydibenzoylmethane,2-methyl-5-tert-butyl-4′-methoxydibenzoylmethane,2,4-dimethyl-4′-methoxydibenzoylmethane, and2,6-dimethyl-4-tert-butyl-4′-methoxydibenzoylmethane.

In another embodiment, the first ultraviolet-absorbing moiety is a UV-Babsorbing moiety. By “UV-B absorbing moiety,” it is meant that themoiety has appreciable absorbance in the UV-B portion (290 nm to 320 nm)of the ultraviolet spectrum. In one embodiment, the criteria forconsideration as a UV-B absorbing moiety is similar to those describedabove for an UV-A absorbing moiety, except that the wavelength range is290 nm to 320 nm.

Examples of suitable UV-B absorbing moieties include 4-aminobenzoic acidand alkane esters thereof; anthranilic acid and alkane esters thereof;salicylic acid and alkane esters thereof; hydroxycinnamic acid alkaneesters thereof; dihydroxy-, dicarboxy-, and hydroxycarboxybenzophenonesand alkane ester or acid halide derivatives thereof; dihydroxy-,dicarboxy-, and hydroxycarboxychalcones and alkane ester or acid halidederivatives thereof; dihydroxy-, dicarboxy-, and hydroxycarboxycoumarinsand alkane ester or acid halide derivatives thereof; benzalmalonate(benzylidene malonate); benzimidazole derivatives (such as phenylbenzilimazole sulfonic acid, PBSA), benzoxazole derivatives, and othersuitably functionalized species capable of copolymerization within thepolymer chain.

Particularly suitable UV-B absorbing moieties include UV-absorbingbenzophenones and UV-absorbing diphenylcyanoacrylate derivatives.Examples of benzophenone derivatives include those known in the art toprovide protection of the skin from UV radiation, for example, such astaught by U.S. Pat. No. 5,776,439. Preferred compounds include2-hydroxy-4-methoxybenzophenone (“oxybenzone”) and2-2′dihydroxy-4-methoxybenzophenone (“dioxybenzone”) and diethylaminehydroxybenzoyl hexyl benzoate (“hydroxybenzophenone”). Examples ofdiphenylcyanoacrylate derivatives include 2-ethylhexyl2-cyano-3,3-diphenyl-2-propenoate (“octocrylene”) and its derivatives.

In one embodiment, the UV-absorbing polymer includes a singleUV-absorbing moiety. In this embodiment, the single UV-absorbing moietyis preferably a UV-A absorbing moiety, and most preferably aUV-absorbing triazole.

In addition to the UV-absorbing moiety, the first repeat unit, A, of theUV-absorbing polymer, generally includes a functional group R′, whichmay be, for example a hydrogen atom, alkyl group (e.g., C₁-C₁₂), or thelike. In one embodiment, R′ has a molecular weight of less than about100, such as less than about 50, such as less than about 30. In onepreferred embodiment R′ is a methyl group. It is preferred that the R′group is free of UV-absorbing moieties.

The molecular weight of the first repeat unit, A, may be from about 150to about 1000, preferably from about 200 to about 700, more preferablyfrom about 200 to about 500.

The number of first repeat units, n, per molecule (e.g., on average),may be from about 1 to about 6000, preferably from about 2 to about3500, more preferably from about 5 to about 2500, and even morepreferably from about 10 to about 1500.

The ultraviolet-radiation absorbing polymer generally includes m molesof a second repeat unit, B. The second repeat unit, B generally includessecond pendant group, R₂ which is linked to the C—C backbone via, forexample, an ester linking group.

The number of second repeat units, m, per molecule (e.g., on average),may be from about 2 to about 6300, preferably from about 3 to about4000, more preferably from about 10 to about 3000, and even morepreferably from about 20 to about 2000.

In one embodiment, the second pendant group is a “spacer group” thatserves to provide an appropriate amount of space between UV-absorbingmoieties (R₁) that are present throughout the UV-absorbing polymer. Inthis embodiment, the second pendant group is free of UV-absorbingmoieties. As such, the second pendant group may also serve to facilitateintimate mixing with other components (e.g., hydrophobic components) inthe composition.

Preferably, the spacer group is sufficient to maintain the hydrophobiccharacter of the polymer. However, the spacer group should not confersuch extraordinary hydrophobicity to the polymer such that it isdifficult to dissolve, disperse, emulsify, or otherwise render theUV-absorbing polymer phase stable in a cosmetically acceptable carrier.As such, the second pendant group, R₂ of the second repeat unit, B, mayinclude either or both of the following: (i) at least one siloxane(—Si—O—) linkage, such as from 1 to about 50 siloxane linkages,preferably from about 1 to about 20 siloxane linkages, and morepreferably from about 1 to about 20 siloxane linkages, even morepreferably from about 1 to about 16 siloxane linkages, even morepreferably from 2 to 15 siloxane linkages, even more preferably from 2to 10 siloxane linkages, and most preferably from 2 to 5 siloxanelinkages.

In one preferred embodiment of the invention, the siloxane linkages arelinearly arranged; in another embodiment the siloxane linkages arebranched. The siloxane linkages may terminate in organic functionalgroups, e.g., an alkyl group, such as a methyl group; (ii) a hydrocarbonmoiety, such as a hydrocarbon moiety having an intermediate number ofcarbon atoms. Suitable examples include C₇-C₁₆ hydrocarbon moieties,such as C₇-C₁₆ alkyl groups. In one preferred embodiment of theinvention, such hydrocarbon moiety is linearly arranged; in anotherembodiment the hydrocarbon moiety is branched.

The second repeat unit, B, also includes a second functional group R′which may be the same or different than the first functional group R′ offirst repeat unit A. That is, second functional group R′ may be, forexample a hydrogen atom, alkyl group (e.g., C₁-C₁₂), or the like. In oneembodiment, R′ has a molecular weight of less than about 100, such asless than about 50, such as less than about 30. In one preferredembodiment R′ is a methyl group. It is preferred that the R′ group isfree of UV-absorbing moieties.

The molecular weight of the second repeat unit, B, may be from about 100to about 1000, preferably from about 100 to about 500, more preferablyfrom about 100′ to about 250.

The UV-absorbing polymers useful in the present invention are preferably“rich” in ultraviolet-absorbing moieties. As such they are highlysuitable for formulation into topical sunscreens. By “rich” inultraviolet-absorbing moieties, it is meant that the percentage by moleof first repeat units, n to total repeat units, n+m may be in a rangefrom about 10% to about 100% (note that when the percentage is 100%, thespacer groups are entirely absent—in which case the UV-absorbing polymermay be a homopolymer with a C—C backbone and pendant groups with one ormore UV-absorbing moieties, but no pendant groups that are free ofUV-absorbing moieties). In certain preferred embodiments, the molepercentage of first repeat units, n, to total repeat units, n+m, is atleast about 5% such as in a range from about 5% to about 90%, or 10% toabout 90%, and in certain embodiments, such as from about 25% to about70%. In certain embodiments, the mole percentage of first repeat units,n, to total repeat units, n+m is from about 25% to about 40%, such asfrom 30% to 40%.

In one embodiment, the ultraviolet absorbing polymer includes no repeatunits other than repeat unit A and repeat unit B, described above. Inanother embodiment, the ultraviolet-radiation absorbing polymer includesone or more additional repeat units. These repeat units may includerepeat units bearing an additional ultraviolet absorbing group, asiloxane group, a hydrocarbon group, or another organic moiety, orcombinations of such groups such as may be linked to the C—C backbonevia, for example, a ester linking group. The additional ultravioletabsorbing group may absorb over a similar spectral range as the firstultraviolet absorbing group present on repeat unit A. Examples of suchUV-absorbing groups include benzotriazoles derivatives and benzophenonederivatives. In another embodiment, the additional ultraviolet absorbinggroup may absorb over a dissimilar spectral range as the firstultraviolet absorbing group.

Repeat unit A, repeat unit B and the additional repeat units may bearranged in various manners. For example, the repeat units may bearranged such they alternate, in blocks of various numbers of repeatunits, or be randomly arranged.

The molecular weight of the ultraviolet radiation-absorbing polymer issufficiently high enough to reduce the likelihood of absorption into theskin, and therefore the body. In one embodiment of the invention, themolecular weight of the ultraviolet radiation-absorbing polymer isgreater than about 2000. In another embodiment, the molecular weight ishigh enough to reduce the likelihood of absorption into the skin, butnot so high such that it is difficult to dissolve, disperse, emulsify,or otherwise make the UV-absorbing polymer phase stable in acosmetically acceptable carrier. As such, the molecular weight of theUV-absorbing polymer may greater than about 2000, but not so high thatthe polymer becomes crosslinked. Preferably, the polymer isuncrosslinked. The molecular weight of the UV-absorbing polymer may befrom about 2000 to about 1,000,000, preferably from about 50,000 andabout 750,000, more preferably from about 50,000 to about 500,000. Inone embodiment, the polymer is a linear polymer (i.e., includes noappreciable branching other than the presence of R₁, R₂, and R′).

In order to reduce the likelihood of penetration of low molecular weightspecies through the skin, the ultraviolet radiation-absorbing polymermay have a (mass or number) fraction of low molecular weight specieswhich is less than about 5%, such as less than about 1%, such as lessthan about 0.1%. By “low molecular weight species,” it is meant thosespecies that have a molecular weight that is less than about 2000.

In order to enhance water-resistance and spreadability, the UV-absorbingpolymer may, in certain embodiments have a low water solubility. Forexample, in certain embodiments, the ultraviolet radiation-absorbingpolymer may have a water solubility that is less than about 3% byweight, preferably less than about 1% by weight. By “water solubility”it is meant the maximum weight percentage of polymer (relative topolymer plus water) that can be placed into 100 grams deionized waterand agitated so that a clear solution is obtained and remains visuallyhomogeneous and preferably transparent at room temperature for 24 hours.

Furthermore, in certain embodiments, the UV-absorbing polymer isdesirably free of ionizable moieties that are commonly present inso-called “polymer latex” compositions to facilitate dispersion of thepolymer in an aqueous system. Examples of ionizable moieties that, inthis embodiment, may be absent include anionics such as sulfate,sulfonate, carboxylate, phosphate, phosphonates; cationics such as:ammonium, including mono-, di-, and trialkylammonium species,pyridinium, imidazolinium, amidinium, poly(ethyleneiminium;zwitterionics such as ammonioalkylsulfonate, ammonioalkylcarboxylate,amphoacetate. A UV-absorbing polymer free of ionizable moieties may forma more durable water repellant coating on the skin and enhancespreadability.

The ultraviolet radiation-absorbing polymer may have a melting point ora glass transition temperature that is, for example, below about 37° C.

It is further desirable that the UV-absorbing polymer have an absorbancein the UV that is sufficiently high so as to make it suitable for use asa sunscreen for the human body. In one embodiment, the polymer, whendissolved in a suitable solvent (e.g., DMSO, ethyl acetate,tetrahydrofuran, or the like) and spread or cast into a thin film, has amolar extinction coefficient measured for at least one wavelength withinthe UV spectrum, and more preferably in the UV-A spectrum, of at leastabout 1000 mol⁻¹ cm⁻¹, such as at least about 2000 mol⁻¹ cm⁻¹, such asat least about 4000 mol⁻¹ cm⁻¹, or even 10,000 or 100,000 or 1,000,000mol⁻¹ cm⁻¹.

Polymers of the present invention may be synthesized, for example bymethods known in the art. For example, suitable polymers may be formedby addition polymerization, such as via free-radical additionpolymerization of suitable ethylenically unsaturated monomers. Theresulting polymer may have its repeat units alternating, block, random,graft, star or other configurations.

For example, the inventive polymer may be made by reacting a firstethylenically unsaturated compound (monomer) that includes anultraviolet-absorbing moiety, with a second compound (monomer) thatincludes, for example in one embodiment, at least one siloxane linkage.In another embodiment, the second ethylenically unsaturated monomerincludes a hydrocarbon moiety, such as a hydrocarbon moiety having anintermediate number of carbon atoms. This reaction may take place in thepresence of an initiator such as AIBN (azobisisobutyronitrile) or1,1′-azobis(cyanocyclohexane) available as VAZO® VA-40 from E.I. DuPontof Wilmington, Del., or other suitable initiators. In one embodiment,the first ethylenically unsaturated compound includes a UV-A absorbingmoiety. The UV-A absorbing moiety may be a benzotriazole. Examples ofsuitable benzotriazole monomers include2′hydroxy-5′-methacryloxyethylphenyl-2H-benzotriazol as well as themethacrylated benzotriazole described in Examples 15 and 19 below. Inanother embodiment, the first ethylenically unsaturated compoundincludes a dibenzoylmethane. One such suitable monomer is amethacrylated dibenzoylmethane shown in Inventive Example 10 below.

The second ethylenically unsaturated compound may include a siloxanelinkage, such as acryloxyalkyl polydimethylsiloxanes. One suitableexample of such a monomer is monomethacryloxypropyl polydimethylsiloxane(mPDMS), such as mPDMS having average 11 siloxane linkages. Othermonomers that include a siloxane that may be suitable includeC₁₆H₃₈O₅Si₄, 2-Propenoic acid, 2-methyl-,3-[3,3,3-trimethyl-1,1-bis[(trimethylsilyl)oxy]-1 disiloxanyl]propylester (also known as “TRIS” monomer). mPDMS and TRIS are commerciallyavailable from Gelest Inc. of Morrisville, Pa.

In another embodiment, the second ethylenically unsaturated compound isan ethylenically unsaturated organosilane. By “ethylenically unsaturatedorganosilane” it is meant, any of various compounds that include atleast one terminal Si—O—R linkage where R is a functional group such asan alkyl, aryl, aralkyl, among other functional groups. One particularlysuitable ethylenically unsaturated organosilane is methacryloxypropyltrimethoxysilane (which has 3 siloxane linkages, from a common siliconatom), commercially available as Z-6030 from Dow Corning of Midland,Mich.

In another embodiment the second ethylenically unsaturated compoundincludes a hydrocarbon moiety, such as one having an intermediate numberof carbon atoms. Suitable examples include acrylates or methacrylateshaving a C₇-C₁₆ alkyl attached thereto. Examples include a C₈ acrylatesuch as isooctyl acrylate H₂C═CHCO₂(CH₂)₅CH(CH₃)₂; a C₁₂ methacrylatesuch as lauryl methacrylate, H₂C═C(CH₃)CO₂(CH₂)₁₁CH₃, and the like.Isooctyl acrylate and lauryl methacrylate are commercially availablefrom Sigma-Aldrich of St. Louis, Mo.

Alternatively, the UV-absorbing polymer may be made bypost-polymerization addition of the pendant groups to the polymer. Forexample, an acrylic polymer having a maleic anhydride functionality maybe synthesized, followed by reaction of that polymer with a UV-monomersuch as avobenzone, thereby chemically attaching the UV-absorbing moietyvia an ester linkage. Suitable maleic anhydride copolymers include forexample PA-18 (octadecene/maleic anhydride copolymer) commerciallyavailable from Chevron Phillips, or Gantrez AN copolymers (PVM/MAcopolymer) commercially available from ISP. Alternatively,N-hydroxysuccinamide ester of (meth)acrylic acid can be used as astarting monomer.

Polymers of the present invention may be used, for example by combiningthe polymer with a suitable cosmetically acceptable carrier as describedbelow. The incorporation of polymers of the present invention into suchcompositions may provide enhanced SPF (primarily UV-B absorbance),enhanced PFA (primarily UV-A absorbance) or enhancement of both.

Topical Composition

In one embodiment, a composition, such as a composition suitable fortopical/cosmetic use for application to the human body (e.g.,keratinaceous surfaces such as the skin or hair), especially the skin,is provided. The composition includes the inventive UV-absorbing polymerdescribed herein. The concentration of the inventive UV-absorbingpolymer may vary from 0.001% to about 100% by weight, preferably fromabout 0.1% to about 50%, more preferably from about 0.5% to about 40% ofthe composition.

The compositions useful in the present invention may be used for avariety of cosmetic uses, including, especially for protection of theskin from UV radiation. The compositions, thus, may be made into a widevariety of delivery forms. These forms include, but are not limited toemulsions (W/O, O/W or multiple emulsions), dispersions, solutions, orcoatings on water soluble or water-insoluble insoluble substrates (e.g.,substrates such as organic or inorganic powders, fibers, or films).Suitable product forms including lotions, creams, gels, sticks, sprays,ointments, mousses, and compacts/powders. The composition may beemployed for various end-uses, such as recreation or daily-usesunscreens, moisturizers, cosmetics/make-up, cleansers/toners,anti-aging products, or combinations thereof.

The compositions of the present invention may be prepared usingmethodology that is well known by an artisan of ordinary skill in thefield of, for example, cosmetics formulation.

In certain preferred embodiments, compositions of the present inventioninclude water and are thus “aqueous compositions.” In certain furtherpreferred embodiments, the composition is an emulsion that includes awater phase and an oil phase. It is particularly preferred that thecomposition includes a continuous water phase in which the UV-absorbingpolymer is stabilized, preferably emulsified. The oil phase may be suchthat it is present in the emulsion in discrete droplets or units havingan average diameter of about one micron to about 1000 microns, morepreferably from about 1 micron to about 100 microns. In an alternativeembodiment, the composition includes a continuous oil phase in which thewater is stabilized, preferably emulsified.

The percentage of water included in the compositions may range from 10%to about 99%, preferably from about 20% to about 80%, more preferablyfrom about 30% to about 70%.

Second UV-Absorbing Polymer

In one particularly preferred embodiment, the composition includes asecond ultraviolet radiation-absorbing polymer. By “second ultravioletradiation-absorbing polymer,” it is meant a compound chemically distinct(with respect to chemical formula, e.g., chemical formula or repeat unitcontent) from the UV-absorbing polymer described above. Broadlyspeaking, the second UV-absorbing polymer may have one of variouschemical backbones (e.g., siloxane or C—C) and one or more UV-absorbingmoieties (UV-A and/or UV-B) either on one or more ends of the moleculeor pending from the backbone. The second UV-absorbing polymer may haveat least 2, more preferably at least about 10 repeat units.

In one embodiment, in order to enhance the synergy between theUV-absorbing polymer of the invention and the second UV-absorbingpolymer, the molecular weight of the second UV-absorbing polymer issimilar to the UV-absorbing polymer of the invention. As such, thesecond UV-absorbing polymer may have a molecular weight of at least2000, such as at least about 5000, such as at least about 10,000. In oneembodiment, the second UV-absorbing polymer has a molecular weight fromabout 5000 to about 200,000. Furthermore, the second UV-absorbingpolymer may have solubility characteristics similar to those of theUV-absorbing polymer of the invention, as specified above (e.g., lessthan about 3% by weight water solubility, preferably less than about 1%by weight).

Applicants have found that UV-absorbance is surprisingly enhanced if afirst UV-absorbing polymer is combined with a second UV-absorbingpolymer, wherein the first UV-absorbing polymer and the secondUV-absorbing polymer have particular features.

For example, in one aspect of the invention, compositions of the presentinvention include a first UV-absorbing polymer that includes a UV-Aabsorbing moiety and the second UV-absorbing polymer that includes aUV-B absorbing moiety. The UV-B absorbing moiety is different than theUV-A absorbing moiety. The first UV-absorbing polymer and the secondUV-absorbing polymer are characterized as capable of providing bothsynergistic SPF and synergistic PFA protection over a mass percent rangeof the first and second UV-absorbing polymers of at least about 40%(defined below). In a preferred embodiment, the first UV-absorbingpolymer and the second UV-absorbing polymer are characterized as capableof providing both synergistic SPF and synergistic PFA protection over amass percent range of at least about 60%.

In order to assess whether a particular combination of two UV-absorbingpolymers provides synergistic SPF protection, the following logarithmicSPF procedure may be used. SPF for (a) the first UV-absorbing polymer,(b) the second UV-absorbing polymer; and (c) the particular blend of thefirst UV-absorbing polymer and the second UV-absorbing polymer aredetermined. SPF is determined by forming a film with the polymer orcomposition to be tested and evaluating using the IN-VITRO SUNPROTECTION TEST METHOD that is described below.

In particular, if the SPF of each individual UV-absorbing polymer(Polymer A and Polymer B) is such that the logarithm of the SPF of theblend is higher than the sum of the logarithms of the unblended polymercomponents, each weighted by their respective mass fractions relative tothe total mass of both UV-absorbing polymers, then the particular blendof UV-absorbing polymers provides synergistic SPF protection. Thecondition for synergy is thus specified below:

Log SPF_(blend) >X _(A) Log SPF_(A) +X _(B) LOG SPF_(B)

For example, if Log SPF of polymer A is 1 and Log SPF of polymer B is1.2 and a blend of the 2 polymers (40% polymer A, 60% polymer B) has aLog SPF of greater than:

[(0.4)×(1)]+[(0.6)×(1.2)]=1.12,

the particular blend provides synergistic SPF.

Similarly, synergistic PFA is determined in the same way. If

Log PFA_(blend) >X _(A) Log PFA_(A) +X _(B) LOG PFA_(B)

the particular blend provides synergistic PFA protection.

PFA, like SPF, is determined according to the IN-VITRO SUN PROTECTIONTEST METHOD, described below.

If the two UV-absorbing polymers can be blended into a single phase(either with a solvent system or with no ingredients other than the twopolymers) and the blend provides both synergistic SPF and synergisticPFA protection, then the particular blend of Polymer A and Polymer B are“capable of providing both synergistic SPF and synergistic PFAprotection.”

By “solvent system,” it is meant a solvent or a blend of solvents, oils,plasticizers or the like that are capable of simultaneously dissolvingboth UV-absorbing polymers over a range of concentrations.

Furthermore, if Polymer A and Polymer B are capable of providing bothsynergistic SPF and synergistic PFA protection for at least 3 differentof mass ratios of the two polymers, (preferably at least 4 differentmass ratios, more preferably at least about 5 different mass ratios—andeach of the mass ratios that are measured are preferably spaced apart byat least 10%, such as 80%/20 and 70%/30), wherein the lowestconcentration of the Polymer A and the highest concentration of thePolymer A are separated by at least about 40%, then the two polymers arecapable of providing both synergistic SPF and synergistic PFA protectionover a mass percent range of the two polymers of at least about 40%.Likewise, if the at least 3 different mass ratios are separated by atleast about 60%, then the UV-absorbing polymers are capable of providingboth synergistic SPF and synergistic PFA protection over a mass percentrange of the two polymers of at least about 60%.” For purposes ofsynergy assessment, by “about X %,” it is meant within +/−1% of X %.

In certain preferred embodiments, (a) the first UV-absorbing polymer isa UV-absorbing polymer according to the invention, i.e., the firstUV-absorbing polymer comprises a C—C backbone and includes a firstpendant group that includes a UV-A absorbing moiety; and furtherincludes a second pendant “spacer” group that includes either a siloxanelinkage and/or intermediate number of carbon atoms; and furthermore (b)the second UV-absorbing polymer includes a UV-B absorbing moiety,different that the UV-A absorbing moiety.

In a preferred embodiment, the second UV-absorbing polymer also includesat least one siloxane (Si—O—) linkage, such as is preferably part of asiloxane backbone. In one embodiment, the siloxane backbone has at leastabout 10 siloxane linkages, such as at least about 50 siloxane linkages.In one preferred embodiment, the second UV-absorbing polymer is adimethicodiethyl benzal malonate, also known as a benzylidene malonatesilicone, such as the filter known as Polysilicone-15. Examples ofsuitable benzylidene malonate silicone includes those described in U.S.Pat. No. 6,193,959 to Bernasconi et al. A particularly suitablebenzylidene malonate includes PARSOL SLX, commercially available fromDSM (Royal DSM N.V.) of Heerlen, Netherlands.

Applicants have found that by utilizing blends that show synergy acrossa wide range of mass ratios, it is possible to provide compositions thathave the benefit of non-penetrating sunscreens and enhanced protectionacross both UV-A and UV-B protection.

In another embodiment, the composition includes a first UV-absorbingpolymer and the second UV-absorbing polymer that are capable ofproviding both synergistic SPF and synergistic PFA protection over amass percent range of the two polymers of at least about 40%; and thecomposition further includes a synergy-promoting solvent system.“Synergy-promoting solvent system” means the following: the solventsystem is such that when used to dissolve the UV-absorbing polymers, theUV-absorbing polymers provide a synergistic blend. In addition to thesynergy promoting solvent system, the composition may have one or moreother classes of ingredients suitable for personal care compositions.

The synergy promoting solvent system may be selected so as to dissolveboth of the UV-absorbing polymers. As such, the components of thesolvent system may have a solubility parameter that is similar to thatof the UV-absorbing polymers. In one embodiment, the synergy promotingsolvent system includes, consists essentially of, or consists of asolvent or plasticizer that does not absorb ultraviolet radiation andhas a dielectric constant (i.e., static permittivity, measured at 20degrees C.) that is from about 3 to about 8, more preferably from about3 to about 6, and even more preferably from 4 to 6). Examples ofsuitable solvents are described in paragraph [0060] of published USpatent application, US20090098367, entitled, “Compositions HavingElongated Particles With Varying Charges and Aspect Ratios,” which isincorporated herein by reference.

In certain embodiments, the solvent is selected from a group consistingof: benzoate esters such as alkyl benzoate esters, in particular C₁₂-C₂₄benzoate esters, such as a C₁₂-C₁₅ benzoate ester (e.g., FINSOLV TN,having a dielectric constant of about 3.8 commercially available fromFinetex Inc. of Elmwood Park, N.J.); dibutyl adipate (e.g., CETIOL B,having a dielectric constant of about 5.1 commercially available fromavailable from Cognis Corporation of Ambler, Pa.), caprylic/caprictriglycerides (having a dielectric constant of about 3.8), andcombinations thereof.

In another aspect, the composition of the present invention includes afirst UV-absorbing polymer including a UV-A absorbing moiety; and asecond UV-absorbing polymer including a UV-B absorbing moiety, whereinthe first UV-absorbing polymer has a PFA/SPF ratio greater than 0.3 andthe second UV-absorbing polymer has a PFA/SPF ratio less than 0.3. Byselecting the first UV-absorbing polymer and the second UV-absorbingpolymer to meet these requirements it is possible to achieve acomposition having a PFA/SPF that is near or equal to 0.3, thusproviding broad spectrum protection.

The first UV-absorbing polymer may be a UV-absorbing polymer of theinvention. However, the first UV-absorbing polymer may have a siloxanebackbone and/or have spacer groups different from those of theUV-absorbing polymer of the invention, and/or be devoid of spacergroups.

Furthermore in order to enhance the magnitude of both SPF and PFA andfurther provide a composition that has broad spectrum protection,Applicants have found that it is desirable for the composition to notonly to include a first UV-absorbing polymer having a UV-A absorber,with a PFA/SPF ratio greater than 0.3; and a second UV-absorbing polymerhaving a UV-B absorber with a PFA/SPF ratio less than 0.3; but also forthe two UV-absorbing polymers to provide both synergistic SPF and PFAprotection at the particular mass ratio in which they are present in thecomposition. In this manner, the magnitude of SPF, and PFA are enhanced,but not at the expense of having a ratio that is removed from 0.3. In arelated embodiment, the composition further includes a synergy-promotingsolvent system.

In another aspect, the composition includes a first UV-absorbing polymerhaving a C—C backbone and including a UV-A absorbing moiety; and asecond UV-absorbing polymer having a siloxane backbone and including aUV-B absorbing moiety.

The first UV-absorbing polymer may be formed by reacting two or moreethylenically unsaturated monomers. As such, it may have a first pendantgroup that includes the UV-A absorbing moiety. It may further include asecond pendant group, such as a spacer group. In one embodiment, thefirst UV-absorbing polymer is a UV-absorbing polymer of the invention.

The second UV-absorbing polymer may have a variety of configurations. Inone embodiment, the UV-absorbing moiety is present on the ends of thepolymer. In a particularly desirable embodiment, the second UV-absorbingpolymer includes a pendant group that includes the UV-B absorbingmoiety.

Applicants have surprisingly found that the combination of a firstUV-absorbing polymer having a C—C backbone and a UV-A absorber; and asecond UV-absorbing polymer having a siloxane backbone and a UV-Babsorber provides broad based synergy in SPF and PFA, whereas variousother combinations of backbone type and UV-absorber type (e.g.,UV-absorbing polymer having a C—C backbone and a UV-A absorber combinedwith a UV-absorbing polymer having a C—C backbone and a UV-B absorbingmoiety) may not provide this desirable feature.

In another aspect, the composition includes a first UV-absorbing polymerhaving an C—C backbone, a first pendant group that includes a first UVabsorber and a second pendant group comprising at least one siloxanegroup, wherein second pendant group is free of UV-chromophores; and asecond UV-absorbing polymer that includes at least one siloxane (e.g.,in its backbone, although this is not necessarily required) and a secondUV absorbing moiety, different than the first UV-absorbing moiety.

Without wishing to be bound by theory, Applicants believe that thesiloxane present in the second pendant group of the first UV-absorbingpolymer enhances blending with the siloxane present in the secondUV-absorbing polymer—thus providing enhanced ability to absorbUV-radiation.

In one preferred embodiment, the second UV-absorbing polymer includes atleast one siloxane (Si—O—Si) linkage, such as may be a part of asiloxane backbone. In one embodiment, the siloxane backbone has at leastabout 10 siloxane linkages, such as at least about 50 siloxane linkages.In one preferred embodiment, the second UV-absorbing polymer includes abenzilydene malonate as a UV-absorbing group. One particularly suitableexample is a dimethicodiethyl benzal malonate, also known as abenzylidene malonate silicone, such as the filter known as“Polysilicone-15.” Examples of suitable benzylidene malonate siliconeincludes those described in U.S. Pat. No. 6,193,959 to Bemasconi et al.A particularly suitable benzylidene malonate includes “PARSOL SLX,”commercially available from DSM (Royal DSM N.V.) of Heerlen,Netherlands.

In another embodiment, the second UV-absorbing polymer includes2-cyano-3,3-diphenyl acrylic acid functional groups, such as are presentin those polymeric sunscreens disclosed in U.S. Pat. No. 6,962,692; U.S.Pat. No. 6,899,866; and/or U.S. Pat. No. 6,800,274; includinghexanedioic acid, polymerized with 2,2-dimethyl-1,3-propanediol,3-[(2-cyano-1-oxo-3,3-diphenyl-2-propenyl)oxy]-2,2-dimethylpropyl2-octyldodecyl ester. This polymer has a low molecular weight (less than2000) and is sold under the trade name “POLYCRYLENE,” commerciallyavailable from the HallStar Company of Chicago, Ill.

In another embodiment the composition further includes one or moreinorganic ultraviolet screening compounds such as inorganic oxidesincluding titanium dioxide, zinc oxide; iron oxides.

In one embodiment, the composition is free of monomeric sunscreens. Inanother embodiment, the composition may further comprise one or moreadditional UV-A and/or UV-B absorbers. Examples of suchabsorbing/reflecting agents include, but are not limited to “monomeric”organic UV filters: methoxycinnamate derivatives such as octylmethoxycinnamate and isoamyl methoxycinnamate; camphor derivatives suchas 4-methyl benzylidene camphor, camphor benzalkonium methosulfate, andterephthalylidene dicamphor sulfonic acid; salicylate derivatives suchas octyl salicylate, trolamine salicylate, and homosalate; sulfonic acidderivatives such as phenylbenzimidazole sulfonic acid; benzonederivatives such as dioxybenzone, sulisobenzone, and oxybenzone; benzoicacid derivatives such as aminobenzoic acid and octyidimethyl para-aminobenzoic acid; octocrylene and other β,β-diphenylacrylates; dioctylbutamido triazone; octyl triazone; butyl methoxydibenzoyl methane;drometrizole trisiloxane; and menthyl anthranilate.

Other suitable UV absorbers/reflectors useful herein can be found inSagarin, Cosmetics Science and Technology, Chapter VIII, pages 189 etseq. and the ICI Handbook page 1672. A list of such compounds is alsodisclosed in U.S. Pat. No. 4,919,934.

In certain embodiments the composition may include one or more compoundssuitable for enhancing photostability. Photostabilizers include, forexample, diester or polyesters of a naphthalene dicarboxylic acid.Examples of diesters and polyesters of a naphthalene dicarboxylic acidare compounds of formulae (X) or (XI):

wherein R₁₆ and R₂₃, independently, are selected from the groupconsisting of a C₁-C₂₂ alkyl, a diol having the structure HO—R₁₈—OH, anda polyglycol having the structure HO—R₁₇—(—O—R₁₈—)_(m5)—OH; R₁₇ and R₁₈,independently, are C₁-C₆ alkenyl; and m5 and m6, independently, are eachin the range of 1 to about 100. Examples, including the synthesis, ofsuch diesters or polyesters of naphthalene dicarboxylic acid aredescribed in U.S. Pat. No. 5,993,789, and include, but not limited to,diethylhexyl naphthalate (HALLBRITE TQ, C.P. Hall Company, Bedford Park,Ill., USA). See Bonda, et al., Allured's Cosmetic & Toiletries Magazine,115(6):37-45 (2000) disclosing the uses of such compounds in sunscreencompositions. In one embodiment, the diester or polyester of anaphthalene dicarboxylic acid can range from about 0.1% to about 30%, byweight, of the total composition (e.g., from about 1% to about 10%, byweight). Other photostabilizers that may be suitable include butyloctylsalicylate, bemotrizanol, diethylhexyl syringylidenemalonate,tris(tetramethylhydroxypiperidinol) citrate, polyester-8, octocrylene,ethylbenzylidene camphor, oxybenzone, amide oils, arylakylbenzoatesamong other photostabilizers.

In one embodiment, the composition further comprises an alkyl benzoatederivative. Examples of alkyl benzoate derivatives are compounds of theformulae (XII) or (XIII):

wherein m7 is 5, 7, or 9 and n is 4, 6, or 8;

wherein m8 is 5 or 7 and p is 4 or 6.

The compounds of formulae (XII) and (XIII) may be formed by typicalesterification and transesterification reactions, e.g., as describe inU.S. Pat. No. 5,783,173. Examples of such long branched chain alkylbenzoates are listed in U.S. Pat. No. 5,783,173 and include, but notlimited to, butyloctyl salicylate (HALLBRITE BHB, C.P. Hall Company,Bedford Park, Ill., USA). In one embodiment, the alkyl benzoatederivative can range from about 0.1% to about 30%, by weight, of thetotal composition (e.g., from about 1% to about 10%, by weight).

The compositions of the present invention may further comprise one ormore other cosmetically active agent(s). A “cosmetically active agent”is a compound that has a cosmetic or therapeutic effect on the skin,e.g., agents to treat wrinkles, acne, or to lighten the skin. In oneembodiment, the agent is selected from, but not limited to, the groupconsisting of: hydroxy acids; benzoyl peroxide; sulfur resorcinol;D-panthenol; hydroquinone; anti-inflammatory agents; skin lighteningagents; antimicrobial and antifungal agents such a miconazole,ketoconazole, and elubial; vitamins such as ascorbic acid; tocopherolsand tocotrienols such as tocopheryl acetate; retinoids such retinol,retinal, retinyl palmitate, retinyl acetate, and retinoic acid; hormonessuch as estrogens and dihydroxyandrostene dione; 2-dimethylaminoethanol;lipoic acid; amino acids such a proline and tyrosine; lactobionic acid;self-tanning agents such as dihydroxy acetone; dimethyl aminoethanol;acetyl-coenzyme A; niacin; riboflavin; thiamin; ribose; electrontransporters such as NADH and FADH2; botanical extracts such as ginkgobiloba, aloe vera, and soy; and derivatives thereof. The cosmeticallyactive agent will typically be present in the composition of theinvention in an amount of from about 0.001% to about 20% by weight ofthe composition, e.g., about 0.01% to about 10% such as about 0.1% toabout 5% by weight of the composition.

Examples of hydroxy acids include, but are not limited, to (i)alpha-hydroxy acids such as glycolic acid, lactic acid, malic acid,citric acid, and tartaric acid, (ii) beta-hydroxy acids such assalicylic acid, and/or (iii) polyhydroxy acids. See, e.g., EuropeanPatent Application No. 273,202.

Examples of derivatives of ascorbic acid include, but are not limitedto, ascorbyl palmitate, magnesium ascorbyl phosphate, sodium ascorbylphosphate, zinc ascorbyl phosphate, ascorbyl glucoside, sodiumascorbate, and ascorbyl polypeptide. An example of a derivative ofhydroquinone includes, but is not limited to, arbutin.

The compositions of the present invention may also comprise one or moreof the following: antioxidants (e.g., ascorbic acid, tocopherols,polyphenols, tocotrienols, BHA, and BHT), chelating agents (e.g., EDTA),and preservatives (e.g., parabens). Examples of suitable antioxidants,preservatives, and chelating agents are listed in pp. 1612-13, 1626, and1654-55 of the ICI Handbook. In addition, the topical compositionsuseful herein can contain conventional cosmetic adjuvants, such as dyes,opacifiers (e.g., titanium dioxide), pigments, and fragrances.

The one or more UV-absorbing compounds in the composition may becombined with a “cosmetically-acceptable topical carrier,” i.e., acarrier for topical use that is capable of having the other ingredientsdispersed or dissolved therein, and possessing acceptable propertiesrendering it safe to use topically. As such, the composition may furtherinclude any of various functional ingredients known in the field ofcosmetic chemistry, for example emulsifiers, emollients/oils/waxes,humectants, thickeners, opacifiers, fragrances, dyes, co-solvents amongother functional ingredients. Furthermore, the composition may beessentially free of ingredients that would render the compositionunsuitable for topical use. As such, the composition may be essentiallyfree of solvents such as volatile solvents, and, in particular, free ofvolatile organic solvents such as ketones, xylene, toluene, and thelike. By “essentially free” it is meant that such ingredients arepresent individually or in combination in concentrations of less thanabout 2%, preferably less than about 1%, more preferably less than about0.5%, and most preferably free of such compounds.

In certain embodiments the composition has a pH that is from about 4.0to about 8.0, preferably from about 5.5 to about 7.0.

In one particularly notable embodiment, the composition includes anemulsifier suitable for stabilizing the UV-absorbing polymer, such as inan oil in water emulsion. Suitable emulsifiers, e.g., such as non-ionicemulsifiers, include those commonly used in personal care products suchas alkyl/fatty alcohols, alkyl/fatty esters, alkyl/fatty glucosides,alkoxylated esters fatty acids, and the like. In another embodiment, thecomposition includes one or more oils or other hydrophobic compounds toaid in spreading and or solubilization of the UV-absorbing polymer.Suitable hydrophobic compounds include oils including mineral oils,petrolatum, vegetable or animal-derived oils (triglycerides and thelike); non-hydrocarbon based oils such as dimethicone, and othersilicone oils as well as silicone gums; fragrance oils; waxes includingpolyethylene waxes, and other mixtures of fatty esters, not necessarilyesters of glycerol.

The compositions of the present invention can be used by topicallyadministering to a mammal, e.g., by the direct laying on or spreading ofthe composition on the skin or hair of a human.

The compositions of the present invention may be prepared usingmethodology that is well known by an artisan of ordinary skill. Specificexamples of inventive polymers, methods, and compositions are describedbelow.

Compositions according to various embodiments of the present inventionconfer one or more important advantages when compared with prior artcompositions. According to certain embodiments, the compositions includeUV-absorbing polymers having a C—C backbone and these often confervarious advantages over those with siloxarie backbones. These advantagesinclude, but are not limited to: greater flexibility in preparation(emulsion, solution, bulk, solution), and/or initiation routes, and/orthe ability to produce higher molecular weights and tailor molecularweight and its distribution and/or reduced contamination by unreactedmonomer.

Other potential advantages include the ability to tailor the placementand sequence of the pendant UV-absorbing chromophore and pendantsiloxane groups, thereby enhancing the likelihood of achieving thedesirable combination of (a) achieving sufficiently high UV-chromophorelevels in the polymer, thereby reducing the concentration of polymerneeded in the ultimate topical sunscreen composition, and thus creatinga variety of sunscreen formulation schemes.

Applicants have also surprisingly found that UV-absorbing polymersaccording to certain embodiments of the invention can be made with theappropriate molecular weight necessary to reduce skin penetration. Theycan also be made sufficiently hydrophobic so as to avoid insufficientwater-repellency (as may be common in polymer lattices or polymers withtoo much hydrophilic character), yet still be sufficiently easy toformulate, have sufficient spreadability on the skin, and yet can stillbe economically produced.

Furthermore, according to certain embodiments of the invention, C—Cbackbone, UV-absorbing polymers possess the ability to be blended withother UV-absorbing materials to create a desirable balance of UVA/UVBprotection. Such blends may also be formulated with superior aestheticswithout necessarily requiring that the formulation include additionalsilicone in the form of silicone oils. Such formulations achieve a highdegree of spreading, as well as waterproofing due to the UV-absorbingpolymer's low water solubility.

The following Examples further illustrate the invention.

Examples 1-3 Preparation of UV-Absorbing Polymers

The following UV-absorbing polymers according to the invention weresynthesized according to the following process: an ethylenicallyunsaturated monomer containing a UV-absorbing group,2-(2′hydroxy-5′-methacryloxyethylphenyl)-2H-benzotriazol, having amolecular weight of 292 grams/mol (referred to herein as “NORBLOC”) wasdissolved in ethyl acetate solvent and added to a three-neck, 100 mlround bottom flask. Twenty five grams of a second ethylenicallyunsaturated monomer, monomethacryloxypropyl polydimethylsiloxane(mPDMS—includes 10 siloxane repeat units per molecule; molecular weightabout 900 grams/mol) was then added.

Under reflux, the reaction mixture was stirred at 65° C. (±15° C.) untilfully dissolved and was purged with nitrogen for 30 minutes.Azobisisobutyronitrine (AIBN; molecular weight 146.21 g/mol) was thenadded using a syringe. The reaction stirred for 16-18 hours and wasmonitored by TLC for the loss of NORBLOC. Once the reaction wascomplete, 100-200 ml of toluene was added to the mixture and heated to80° C. while stirring. The reaction was cooled to ambient temperatureand 500 ml of ice-cold methanol was added precipitating out the polymer.Two additional washes of the precipitate with 500 ml of ice-coldmethanol were performed removing any unreacted monomers. The precipitatewas dissolved in ethyl acetate, concentrated down by rotary evaporationand put under vacuum for 24 hours.

Three polymers, Examples 1-3, were separately prepared by varying theamount of NORBLOC and AIBN. The amount of solvent used was 4, 7, and 10g, respectively. The percentages by weight of reactants (i.e., NORBLOCand mPDMS), are as shown in Table 1 below:

TABLE 1 Example Ex. 1 Ex. 2 Ex. 3 mPDMS 95.15% 91.35% 86.72% Norbloc4.17% 8.00% 12.66% AIBN 0.68% 0.65% 0.62%Table 2 shows the molar ratios, as calculated, for the reactants for thesame examples:

TABLE 2 Example Ex. 1 Ex. 2 Ex. 3 mPDMS 83.33% 74.08% 64.56% Norbloc12.50% 22.22% 32.28% AIBN 4.17% 3.70% 3.16%

The polymers were analyzed by Gel Permeation Chromatography for variousmeasures of molecular weight, and polydispersity. The results are shownin Table 3 below:

TABLE 3 Example Ex. 1 Ex. 2 Ex. 3 Mw 684,057 166,459 162,957 Mn 88,19451,173 59,505 Mz 3,480,297 478,776 425,511 Mw/Mn 7.76 3.26 2.74 MP166,723 99,588 98,728 Mz + 1 7,009,308 1,059,361 856,469 Polydispersity7.68 3.28 2.65

Examples 4-8 Preparation of UV-Absorbing Polymers and NORBLOCHomopolymer

UV-absorbing polymers according to the invention similar to those ofExamples 1-3 were prepared, except that the mass of solvent was varied(5 grams for Ex. 4 and 30 ml for Ex. 5-8). The amounts of AIBN andNORBLOC were also varied. Ex. 8 was prepared as a homopolymer (nomPMDS). The mole percents of reactants are given in Table 5 below:

TABLE 5 Example Ex. 8 Ex. 4 Ex. 5 Ex. 6 Ex. 7 (comparative) mPDMS 80.0%48.9% 29.8% 6.7% 0.00% Norbloc 16.0% 48.4% 68.1% 91.9% 96.4% AIBN 4.0%2.7% 2.1% 1.4%  3.6%

Example 9 UV-Absorbance at 5 Wt. Percent Chromophore—Comparison ofUV-Absorbing Polymers and NORBLOC Homopolymer

The UV-absorbing polymers of Ex. 6, Ex. 5, and the homopolymer of Ex. 8were each separately dissolved in THF. The concentration of polymer waschosen such that in each case the total concentration of chromophore insolution was 5%. Each solution was tested according to the “IN-VITRO SUNPROTECTION TEST METHOD” described below.

In-Vitro Sun Protection Test Method:

The baseline transmission of a PMMA plate (substrate) withoutapplication of any test materials applied thereto was measured. Testsamples were prepared by providing a sample of polymer. (Blends may alsobe tested by this method. The polymer(s) can be tested without anyadditional additives; with a solvent system, or as a part of a personalcare composition that may include solvent and/or additionalingredients.)

Each sample was separately applied to a PMMA plate (available fromHelioscience, Marseille, France) using an application density of 2 microliters of solution per square centimeter of substrate, rubbing in into auniform thin layer with the operator's finger, and allowed to dry. Threesuch samples were done for each test material. The samples were thenallowed to dry for 15 minutes before measurement of absorbance usingcalibrated Labsphere® UV-1000S UV transmission analyzer (Labsphere,North Sutton, N.H., USA). The absorbance measures were used to calculateSPF and PFA indices (biological protection factor in the UVA based).

SPF and PFA were calculated using methods known in the art—see equation(1) below for calculation of SPF:

$\begin{matrix}{{SPF}_{i\; n\mspace{14mu} {vitro}} = \frac{\int_{\lambda = {290\; n\; m}}^{\lambda = {400\; n\; m}}{{E(\lambda)}*{I(\lambda)}*{\lambda}}}{{\int_{\lambda = {290\; n\; m}}^{\lambda = {400\; n\; m}}{{E(\lambda)}*{I(\lambda)}*10^{- {A_{0}{(\lambda)}}}*{\lambda}}}\;}} & (1)\end{matrix}$

where:

-   -   E(λ)=Erythema action spectrum    -   I(λ)=Spectral irradiance received from the UV source    -   A0(λ)=Mean monochromatic absorbance of the test product layer        before UV exposure    -   dλ=Wavelength step (1 nm)

The calculation of PFA (i.e., UVAPF) is calculated in a similar manner,except that the wavelength range is 320 nm to 400 nm.

FIG. 1 shows the absorbance spectra for the UV-absorbing polymers ofExamples 5 and 6 and the homopolymer of Example 8.

PFA and SPF were calculated and are shown in Table 6, below:

TABLE 6 % Polymer in % Chromophore Polymer Solution in Solution SPF PFAEx. 8 5 5 7.2 5.9 Ex. 6 12.5 5 15.3 9 Ex. 5 20 5 15 7.6

The results indicate that the copolymers of Ex. 5 and Ex. 6, each ofwhich includes the “spacer” repeat unit, mPDMS, quite surprisingly hadhigher SPF and PFA than the homopolymer of Ex. 8, even though eachsample contained the same amount of total chromophore. Thus, it appearsthat by using mPDMS as a comonomer, a surprisingly beneficialimprovement in UV-absorbance is achieved as compared with a polymer inwhich such a spacer is absent.

Example 10

The following prophetic example is provided for synthesizing aUV-absorbing polymer of the invention. The polymer is similar to thepolymer of Examples 4-7, except that the UV-absorbing group is adibenzoylmethane.

Step 1—Protection of the phenol: In this step, avobenzone is reactedwith a dihydropyran to protect the phenolic hydroxyl group.

Step 2—Coupling reaction to prepare the beta diketone (condensation): Inthis step, the beta diketone is prepared by making a solution of theenolate, and adding the acid chloride dropwise. Excess of the enolaterelative to the beta diketone is used.

Step 3—Deprotection of the THP ether

Step 4—Methacrylation of the phenol: In this step methacrylateddibenzoylmethane (an ethylenically unsaturated monomer) is prepared byesterifaction with methacrylic anhydride.

Step 5—Polymerization: An acrylic copolymer of dibenzoylmethane andmPDMS is prepared in a manner similar (AIBN initiated polymerization,precipitation addition via cold methanol) to the method for synthesizingthe polymers described above, with reference to Examples 1-4.

Example 11

The UV-absorbing polymer of Ex. 3 was blended with a second UV-absorbingpolymer, PARSOL SLX. The polymer of Ex. 3, PARSOL SLX, and variousblends of the two were tested for SPF and PFA. No additional ingredients(e.g., solvents, oils, etc.) were added to the test samples. Table 7below shows the results.

TABLE 7 Polymer Blend SPF PFA PFA/SPF Ex. 3, Pure 14.8 6.5 0.44 ParsolSLX, Pure 16.7 1.1 0.07 50% Ex. 3, 50% SLX 64.7 6.4 0.10 60% Ex. 3, 40%SLX 34.5 4.8 0.14 80% Ex. 3, 20% SLX 47.0 7.8 0.17 95% Ex. 3, 5% SLX27.8 7.5 0.27 96% Ex. 3, 4% SLX 23.9 7.0 0.29 98% Ex. 3, 2% SLX 28.4 8.40.30

The results indicate that when controlled for total amount of sunscreen,the blends of Ex. 3 and PARSOL SLX showed significantly betterperformance than either polymer alone. This indicates, surprisingly,that synergistic UV-absorbance is provided by the various blends of aUV-absorbing polymer according to the invention, having a C—C backbone,a pendant UV-A group and a pendant spacer group that includes asiloxane, which polymer is free of ionizable moieties, with asiloxane-backbone polymer having UV-B absorbing moieties. The resultsshow that it is further possible to provide the particularly desirablebut typically difficult to achieve combination of high values of SPF(e.g., greater than 20), high PFA (e.g., greater than 5), and high ratioof PFA/SPF (e.g., greater than 0.2).

Example 12

The following personal care composition, shown below in Table 8, wasmade using emulsification techniques known in the art of cosmeticchemistry. The composition was a water in oil emulsion (water as theexterior phase) and included two UV-absorbing polymers, emulsifiers(SIMUSOL, MONTANOV) that served to emulsify the UV-absorbing polymer, ahumectant (glycerin), preservatives, a thickener (SIMULGEL polymer), andpH adjusters.

A main vessel was charged with water, to which glycerine, parabens, andphenoxyethanol were added. The vessel was then heated gradually to 75°C. An oil phase premix was made by mixing the polymer of Ex. 6 withPARSOL SLX and DC 246, SIMUSOL, MONTANOV, and cocoate BG. The oil phasepremix was then heated slowly to 75° C. Once the two vessels reached 75°C., the oil phase premix was added to the main vessel. They were mixedfor 15 minutes and held at 75° C. After 15 minutes, SIMULGEL was addedand mixed for 5 minutes while the vessel was kept at 75° C. The vesselwas then slowly cooled to 30° C. and pH was adjusted to between 5 and 6with citric acid or sodium hydroxide.

TABLE 8 Trade name INCI or CTFA name Wt. % water aqua 68 glycerineGlycerin 3 methyl paraben Metylparaben 0.2 propyl paraben Propylparaben0.1 phenoxyethanol Phenoxyethanol 0.7 Polymer of Inventive Polymer 10example, Ex. 6 PARSOL SLX Polysilicone-15 1 DC246 Cyclohexasiloxane and3 Cyclopentasiloxane SIMUSOL 165 PEG-100 Stearate and 1 GlycerylStearate MONTANOV 68 Cetearyl Alcohol and 3 Cetearyl Glucoside cocoateBG Butylene Glycol Cocoate 10 SIMULGEL EG Sodium Acrylate/Sodium 0.5Acryloyldimethyl Taurate Copolymer and Isohexadecane and Polysorbate 80citric acid citric acid 0.1 sodium hydroxide sodium hydroxide 0.1

-   -   The composition had good spreadability and did not leave any        brittle, flaky residue on the skin.

Example 13A Preparation of UV-Absorbing Polymer

The following UV-absorbing polymer of the invention was synthesizedaccording to the following process. 4.6 grams of a first ethylenicallyunsaturated monomer, isooctyl acrylate (H₂C═CHCO₂(CH₂)₅CH(CH₃)₂);molecular weight 184.3 grams/mol) and 8 grams of NORBLOC, were added toa three-neck, 500 ml round bottom flask equipped with an additionfunnel. 50 ml of ethyl acetate was then added. 7.4 grams of isooctylacrylate and 10 ml of ethyl acetate were added to the addition funnel,attached to the flask.

Under reflux, the reaction mixture was stirred at 65° C. (±15° C.) untilfully dissolved and was purged with nitrogen for 30 minutes. 200 mg. Ofazobisisobutyronitrine (AIBN; 146.21 g/mol) was dissolved in 5 ml ofethyl acetate and then added using a syringe. The isooctylacrylate/ethyl acetate solution was then added dropwise over a period of90 minutes into the reaction solution. The reaction stirred for 16-18hours and was monitored by TLC for the loss of NORBLOC. Once thereaction was complete, the reaction was cooled to 25 C. 500 ml of icecold methanol was added, precipitating out the copolymer. Two additionalwashes were performed removing any unreacted monomers. The precipitatewas put under vacuum for 24 hours. Product yield was 75% (15 g) byweight percent. The mass ratio of NORBLOC to isooctyl acrylate was40%/60%=2:3.

Example 13B Preparation of UV-Absorbing Polymer

A synthesis similar to Example 13A was conducted, however, the amountsof reactants and solvents were scaled up to approximately 10 times theamounts listed in Example 13A. Before the ice-cold methanol was added,200-400 ml of the ethyl acetate solvent was removed using a rotaryevaporator. One liter of ice cold methanol was added to precipitate thecopolymer. The subsequent washing was conducted as above. Yield was 75%(150 grams of polymer). The mass ratio of NORBLOC to isooctyl acrylatewas 40%/60%=2:3.

Example 14

Blends of four separate combinations of UV-absorbing polymers in asolvent system were prepared. In each case, the blends consisted of 90%by weight of solvent and 10% by weight of a mixture of two UV-absorbingpolymers. The blends were prepared by dissolving two UV-absorbingpolymers in a solvent system consisting of FINSOLV TN and FINSOLV TPP.The solvent system was 98.89% FINSOLV TN and 1.11% FINSOLV TPP. Afterdissolving the UV-absorbing polymer, the resulting solution was 89%FINSOLV TN, 1% FINSOLV TPP (itself a blend of 3 benzoate esters), and10% total UV-absorbing polymer(s). Similarly, solutions of singlepolymers in the solvent system were also prepared. The selection andmass ratio of UV-polymers was varied as shown in Table 9 below:

TABLE 9 SPF PFA synergy* synergy* PFA/ Ref. # Polymer Blend SPF log SPFlog SPF (Y/N) PFA log PFA log PFA (Y/N) SPF Ex. 14a Polymer of Ex. 64.820 0.683 — — 3.320 0.521 — — 0.689 Ex. 14b Parsol SLX 3.700 0.568 — —0.800 −0.097 — — 0.216 Ex. 14c Ex. 6 90%/10% SLX 4.800 0.681 0.672 Y3.000 0.477 0.459 Y 0.625 Ex. 14d Ex. 6 50%/50% SLX 6.300 0.799 0.626 Y2.200 0.342 0.212 Y 0.349 Ex. 14e Ex. 6 60%/40% SLX 5.900 0.771 0.637 Y2.400 0.380 0.274 Y 0.407 Ex. 14f Ex. 6 10%/90% SLX 4.300 0.633 0.580 Y1.000 0.000 −0.035   Y 0.233 Ex. 14a Polymer of Ex. 6 4.820 0.683 —3.320 0.521 — — 0.689 Ex. 14g Polycrylene (“PC”) 3.000 0.477 — 1.0000.000 — — 0.333 Ex. 14h Ex. 6 90%/10% PC 6.900 0.839 0.662 Y 4.000 0.6020.469 Y 0.580 Ex. 14i Ex. 6 50%/50% PC 3.000 0.477 0.580 N 1.900 0.2790.261 Y 0.633 Ex. 14j Ex. 6 60%/40% PC 3.700 0.568 0.601 N 2.400 0.3800.313 Y 0.649 Ex. 14k Ex. 6 10%/90% PC 2.900 0.462 0.498 N 1.100 0.0410.052 N 0.379 Ex. 14l Polymer of Ex. 13A 5.900 0.771 — — 3.600 0.556 —0.610 Ex. 14g Polycrylene (“PC”) 3.000 0.477 — — 1.000 0.000 — 0.333 Ex.14m Ex. 13A 90%/10% PC 5.500 0.740 0.741 N 3.300 0.519 0.501 Y 0.600 Ex.14n Ex. 13A 60%/40% PC 4.500 0.653 0.653 N 2.500 0.398 0.334 Y 0.556 Ex.14l Polymer of Ex. 13A 5.900 0.771 — — 3.600 0.556 — — 0.610 Ex. 14bParsol SLX 3.700 0.568 — — 0.800 −0.097 — — 0.216 Ex. 14o Ex. 13A90%/10% SLX 6.740 0.829 0.751 Y 3.480 0.542 0.491 Y 0.516 Ex. 14p Ex.13A 60%/40% SLX 6.100 0.785 0.690 Y 2.600 0.415 0.295 Y 0.426 Ex. 14qEx. 13A 10%/90% SLX 6.050 0.782 0.588 Y 1.300 0.114 −0.032   Y 0.215

In order to test for synergy, log SPF* and log PFA* were calculatedusing the mass percent of each of the UV-absorbent polymers in theblend. As discussed previously, if log SPF>log SPF*, synergy wasrecorded in the above table as “Y” for yes or “N” for no. Similarcalculations were performed for log PFA*.

The blend of Ex. 6 and PARSOL SLX provided synergy in both SPF and PFAacross the entire mass percent range tested—a concentration range of80%.

The blend of Ex. 13A and PARSOL SLX provided synergy in both SPF and PFAacross the entire concentration range tested—a concentration range of80%.

The blend of Ex. 6 and POLYCRYLENE provided synergy PFA only across aconcentration range (90-60) of 30%, whereas synergy was only identifiedat one particular concentration (Ex. 14h; 90% Ex. 6, 10% PC) for SPF.

The blend of Ex. 13A and POLYCRYLENE provided synergy PFA synergy forthe two concentrations tested, whereas no synergy was provided in SPF.

Example 15 Preparation of UV-Absorbing Monomer

An acid form of TINUVIN 213 (Ciba, Inc) was prepared, as follows: 40.0 gof TINUVIN 213 was added to a 2 liter, round bottom flask equipped witha stir bar and addition funnel. 1 liter of methanol and was added andstirred until homogenous. 400 mL dH₂O containing 17 g KOH was addeddropwise through the addition funnel, turning the yellow solution adark, amber orange color. The reaction stirred for 24 hours and wasmonitored by TLC. After the reaction was complete about 900 mL ofsolvent was distilled off by rotary evaporation. 1N HCl (aq) was added,until a pH of 1 was achieved by litmus paper, precipitating a whiteprecipitate. The white precipitate was filtered and washed with 1N HCl(aq) 3×1 L. It was then redissolved in 1 L CHCl₃ and an organicextraction was performed with 2×600 mL 1N HCl (aq). The organic layerwas collected, dried over anhydrous Na₂SO₄, filtered, concentrated downby rotary evaporation and dried under vacuum overnight at 50° C., toform an acid form of TINUVIN 213, with a yield of about 90%.

An ethylenically unsaturated, UV-absorbing monomer was prepared from theacid form of TINUVIN 213, as follows. A 500 mL, 3-neck round bottomflask equipped with a Freidrich condenser and stir bar was dried undervacuum and a heating gun for 10 minutes. 9.55 g (0.028 mol) of TINUVIN213 acid (prepared above), 200 mL diethyl ether and 1.3 mL DMF was addedto the round bottom. 2.75 mL (0.037 mol) thionyl chloride was slowlyadded to the mixture. The mixture stirred until homogenous (2-3 hours)except for a small amount of the Vilsmeier salt. 7 g of anhydrous Na₂CO₃was added followed by slowly adding 18.33 g (0.141 mol) 2-hydroxyethylmethacrylate (HEMA). The reaction proceeded overnight and was monitoredby TLC. Once the reaction proceeded to completion, the sodium carbonatewas filtered off and the solution was added to a 1 L separatory funnel.50 mL EtOAc and 100 mL hexane was added to the funnel. An organic washwas performed 5×300 mL with a 2% NaCl (aq) solution, discarding theaqueous phase. A 2×300 mL 5% Na₂CO₃ (aq) solution was then added,precipitating any remaining starting material. The precipitate wasfiltered off and the process was repeated until no precipitate wasformed during the basic aqueous wash. A yellow, organic layer wasthereby collected and dried over anhydrous Na₂SO₄, filtered andconcentrated down by rotary evaporation. The yellow material wasredissolved in a minimal amount of heptane and let sit overnight at roomtemperature to recrystallize. Recrystallization was further enhanced byplacing the flask in a refrigerator for up to 48 hours, to form amethacrylated form of TINUVIN 213, with a yield of about 40%.

Example 16 Preparation of UV-Absorbing Polymer

A UV-absorbing polymer according to the invention was prepared asfollows: 4.0 g TINUVIN 213 methacrylate as prepared in Example 15, 5.0 gZ-6030 silane (available from Dow Corning of Midland, Mich.), 1.0 g AIBNinitiator and 65 mL ethyl acetate (EtOAc) were added to a 100 mL roundbottom flask equipped with a Freidrich condenser and stir bar. Themixture was purged with nitrogen for 10 minutes then heated under refluxat 65° C. for 24 hours. The EtOAc was then distilled off by rotaryevaporation and 4.2 g of CETIOL B (dibutyl adipate, available fromCognis Corporation of Monheim, Germany) was added to the round bottomyielding a 70 wt % of UV-absorbing polymer, 30 wt. % CETIOL B.

Example 17 Preparation of UV-Absorbing Polymer

A UV-absorbing polymer according to the invention was prepared in amanner identical to Example 16, except that 5.0 grams of laurylmethacrylate was substituted for Z-6030 silane, again yielding 70 wt. %of UV-absorbing polymer, 30 wt % CETIOL B.

Example 18 Preparation of UV-Absorbing Polymer

A UV-absorbing polymer according to the invention was prepared in amanner identical to Example 16, except that 5.0 grams of isooctylacrylate was substituted for Z-6030 silane, again yielding 70 wt. % ofUV-absorbing polymer, 30 wt % CETIOL B.

Example 19 Preparation of UV-Absorbing Monomer

An acid form of TINUVIN 109 (Ciba, Inc) was prepared, as follows. 21.21g of TINUVIN 109 was added to a 1 liter, round bottom flask equippedwith a stir bar and addition funnel. 300 mL of ethanol and was added andstirred until homogenous. 100 mL aqueous NaOH containing 10 mL of 50 wt% NaOH(aq) and 90 mL deionized water was added dropwise through theaddition funnel, turning the yellow solution a dark, amber orange color.The reaction stirred for 24 hours and was monitored by TLC. After thereaction was complete about 200 mL of solvent was distilled off byrotary evaporation. 1N HCl (aq) was added, until a pH of 1 was achievedby litmus paper, precipitating a white precipitate. The whiteprecipitate was filtered and washed with 1N HCl (aq) 3×500 mL. It wasthen redissolved in 500 mL CHCl₃ and an organic extraction was performedwith 2×300 mL 1N HCl (aq). The organic layer was collected, dried overanhydrous Na₂SO₄, filtered, concentrated down by rotary evaporation anddried under vacuum overnight at 50° C., to form an acid form of TINUVIN109, with a yield of about 90%.

An ethylenically unsaturated, UV-absorbing monomer was prepared from theacid form of TINUVIN 109, as follows. A 500 mL, 3-neck round bottomflask equipped with a Freidrich condenser and stir bar was dried undervacuum and a heating gun for 10 minutes. 6.78 g (0.020 mol) of TINUVIN109 acid (prepared above), 150 mL diethyl ether and 3 mL DMF was addedto the round bottom. 2.09 mL (0.0286 mol) thionyl chloride was slowlyadded to the mixture. The mixture stirred until homogenous (2-3 hours)except for a small amount of the Vilsmeier salt. 7 g of anhydrous Na₂CO₃was added followed by slowly adding 7.8 g (0.06 mol) 2-hydroxyethylmethacrylate (HEMA). The reaction proceeded overnight and was monitoredby TLC. Once the reaction proceeded to completion, the sodium carbonatewas filtered off and the solution was added to a 1 L separatory funnel.50 mL EtOAc and 100 mL hexane was added to the funnel. An organic washwas performed 5×300 mL with a 2% NaCl (aq) solution, discarding theaqueous phase. A 2×300 mL 5% Na₂CO₃ (aq) solution was then added,precipitating any remaining starting material. The precipitate wasfiltered off and the process was repeated until no precipitate wasformed during the basic aqueous wash. A yellow, organic layer Wasthereby collected and dried over anhydrous Na₂SO₄, filtered andconcentrated down by rotary evaporation. The yellow material wasredissolved in a minimal amount of heptane and let sit overnight at roomtemperature to recrystallize. Recrystallization was further enhanced byplacing the flask in a refrigerator for up to 48 hours, to form amethacrylated form of TINUVIN 109, with a yield of about 40% and amelting point of about 42° C.

Example 20 Preparation of UV-Absorbing Polymer

A UV-absorbing polymer according to the invention was prepared asfollows: 4.0 g TINUVIN 109 methacrylate as prepared in Example 19, 5.0 gZ-6030 silane (available from Dow Corning of Midland, Mich.), 1.0 g AIBNinitiator and 65 mL ethyl acetate (EtOAc) were added to a 100 mL roundbottom flask equipped with a Freidrich condenser and stir bar. Themixture was purged with nitrogen for 10 minutes then heated under refluxat 65° C. for 24 hours. The EtOAc was then distilled off by rotaryevaporation and 4.2 g of CETIOL B (dibutyl adipate, available fromCognis Corporation of Monheim, Germany) was added to the round bottomyielding a 70 wt % of UV-absorbing polymer, 30 wt. % CETIOL B. [40%TINUVIN 109, 50% silane, 10% initiator]

Example 21 Preparation of UV-Absorbing Polymer

A UV-absorbing polymer according to the invention was prepared in amanner identical to Example 20, except that 5.0 grams of laurylmethacrylate was substituted for Z-6030 silane, again yielding 70 wt. %of UV-absorbing polymer, 30 wt % CETIOL B.

Example 22 Preparation of UV-Absorbing Polymer

A UV-absorbing polymer according to the invention was prepared in amanner identical to Example 20, except that 5.0 grams of isooctylacrylate was substituted for Z-6030 silane, again yielding 70 wt. % ofUV-absorbing polymer, 30 wt % CETIOL B.

Example 23 UV-Absorbance—Comparison of UV-Absorbing Polymers HavingDifferent UV-Absorbing Chromophores

The UV-absorbing polymer of Example 20 and the UV-absorbing polymer ofExample 6 were separately dissolved in CETIOL B, each to a concentrationby weight of 20%. Since each of the polymers contained 40% UV-absorbingchromophore by weight, each sample contained 8% (20%×40%) by weightchromophore. The IN-VITRO SUN PROTECTION TEST METHOD was performed onboth materials in order to compare the ability of each to absorb UVradiation. The results are shown in Table 10 below:

TABLE 10 % Polymer in % Chromophore Polymer CETIOL B in Solution SPF PFAEx. 20 20 8 11.59 9.43 Ex. 6  20 8 12.49 5.01The results indicate that, when tested in CETIOL B, the polymer of Ex.20, which included TINUVIN 109 as the UV-absorbing chromophore hadsuperior UV-A absorbing properties as compared with the polymer of Ex.6, which had NORBLOC as the UV-absorbing moiety. The ratio of PFA/SPFfor the polymer of Ex. 20 was 0.89, whereas the PFA/SPF ratio for thepolymer of Ex. 8 was only 0.40. This suggests that, by choosing theTINUVIN 109 as the UV-absorbing moiety, one can achieve even higherlevels of UV-A protection. Furthermore, it suggests that by choosing theTINUVIN 109, one should be able to meet the desirable minimum ratio ofPFA/SPF (0.33), yet still achieve a high SPF.

Example 24

A composition including a UV-absorbing polymer was prepared. Thecomposition consisted of ingredients shown in Table 11 below:

TABLE 11 Trade Name INCI or CTFA Name Percentage Water Water 59.3Pemulen TR 1 Acrylates/C10-30 alkyl acrylate 0.2 crosspolymerSPECTRAGARD caprylyl glycol, hexylene glycol, 0.6 methylisothiazolinoneARLACEL 165 Glyceryl Stearate, PEG-100 1.7 Stearate AMPHISOL K Potassiumcetyl phosphate 0.7 Polymer of Example 20 UV-absorbing polymer 20.0CETIOL B Dibutyl adipate 6.0 FINSOLV TN C12-C15 alkyl benzoate 3.0MYGLIOL 812 Caprylic/capric triglycerides 7.0 LANETTE 16 Cetyl alcohol0.5 COSMEDIA ATH Sodium Polyacrylate & Ethylhexyl 1.0 Stearate &Trideceth-6 Total 100 PEMULEN TR-1 is available from Noveon Inc. ofCleveland, Ohio ARLACEL 165 is available from Uniqema Inc. of Chicago,Illinois AMPHISOL K is available from DSM Nutritional Products ofParsippany, NJ CETIOL B and LANETTE 16 are available from Cognis CareChemicals of Monheim, Germany FINSOLV TN is available from Finetex Inc.of Elmwood Park, NJ MYGLIOL 812 is available from Sasol Germany GmbH ofWitten, Germany SPECTRAGARD is available from Inolex Chemical Company ofPhiladelphia, Pennsylvania

The composition of Example 24 was made by first preparing a water phaseby mixing water and PEMULEN and heating to 85 C. A small amount ofsodium hydroxide was added to neutralize the PEMULEN to a pH of 5.5-6.0.An oil phase was then prepared by mixing the remainder of theingredients (except the COSMEDIA ATH and SPECTRAGARD) together, addingit to the water phase, and homogenizing the two phases using a mixer setat 3500 rpm for 5 minutes. The COSMEDIA ATH was then slowly added andthe mixture was allowed to cool to 30 C. SPECTRAGARD was then added,mixed gently, and allowed to cool to room temperature. The compositionof Example 24 exhibited excellent spreadability and aesthetics.

It is understood that while the invention has been described inconjunction with the detailed description thereof, that the foregoingdescription is intended to illustrate and not limit the scope of theinvention, which is defined by the scope of the appended claims. Otheraspects, advantages, and modifications are within the claims.

1-12. (canceled)
 13. A UV-absorbing polymer having the followingchemical structure:

wherein R₁ is a first pendant group that comprises a UV-absorbingtriazole; R₂ is a second pendant group that comprises: a) 1 to about 50siloxane linkages, b) a saturated or unsaturated hydrocarbon moietyhaving 7 to 16 carbon atoms, or c) a combination thereof, R₂ being freeof UV-absorbing moieties; each R′ is independently H or C₁ to C₁₂ alkyl,n is 1 to 6000; and m is 2 to 6300, said UV-absorbing polymer having aweight average molecular weight of at least about 2000 and comprising atleast about 5 mole % of R₁.
 14. The UV-absorbing polymer of claim 13,wherein R′ is methyl.
 15. The UV-absorbing polymer of claim 13, whereinn is about 2 to about
 3500. 16. The UV-absorbing polymer of claim 13,wherein m is about 3 to about
 4000. 17. The UV-absorbing polymer ofclaim 13 having a weight average molecular weight of about 2000 to about1,000,000.
 18. The UV-absorbing polymer of claim 13, wherein R₁comprises a UV-absorbing moiety having the formula:

wherein each R₁₄ is independently selected from the group consisting ofhydrogen, C₁-C₂₀ alkyl, alkoxy, acyl, alkyloxy, alkylamino, and halogen;each of R₁₅ and R₂₂ are independently selected from the group consistingof hydrogen, C₁-C₂₀ alkyl, alkoxy, acyl, alkyloxy, and alkylamino, atleast one of R₁₅ and R₂₂ not being hydrogen; and R₂₁ is selected fromC₁-C₂₀ alkyl, alkoxy, acyl, alkyloxy, and alkylamino.
 19. TheUV-absorbing polymer of claim 18, wherein R₁₄ is a halogen.
 20. TheUV-absorbing polymer of claim 18, wherein the UV-absorbing triazole is acompound of Formula I in which R₁₄ is a halogen, R₁₅ is a butyl groupand R₂₁ is —CH₂CH₂CO₂C₈H₁₇.
 21. The UV-absorbing polymer of claim 13free of ionizable moieties.
 22. The UV-absorbing polymer of claim 13,wherein R₂ is derived from monomethacryloxypropyl polydimethylsiloxane.23. The UV-absorbing polymer of claim 13, wherein R₂ is derived frommethacryloxypropyl trimethoxysilane.
 24. The UV-absorbing polymer ofclaim 13, wherein R₁ is2-(2′hydroxy-5′-methacryloxyethylphenyl)-2H-benzotriazol.